Spectrum resources are the fundamental media for communications and it is expected that the spectrum efficiency can be maximized due to limited spectrum resources.
Different wireless access technologies are developed to improve the spectrum efficiency. However, there is almost no spectrum and load switching among all wireless access technologies in existing communication networks, i.e. there are few mutual cooperative operations, which brings about the result that spectrum usage is relatively fixed and not flexible enough, and reduces the spectrum efficiency, e.g. the spectrum load of some wireless access technologies is relatively light while the spectrum load of some wireless access technologies is relatively heavy. Dynamic spectrum allocation cannot be realized because of the lack of interaction and cooperation among the access technologies.
Currently, a system reallocation technology is being discussed in the industry. The relocation refers to the adjustment of air interface parameters or configurations in wireless communication technologies, e.g. cell deletion or establishment, parameter adjustment of basebands or radio frequencies, and adjustment of return links etc. Spectrum allocation, which may be performed during system reconfiguration, needs to consider the problem of interference suppression. However, there is no method which can allocate spectrums during system reconfiguration and suppress interference effectively.